Four studies illustrate the range of investigations underway in the CFRS. One of the central challenges of object identification and categorization is the ability to recognize and organize category-related objects independent of their orientation, where they appear in the visual field, and so forth. For object perception and cognition to proceed with any degree of organization, order, or coherence, both biological and environmental variation must be transcended. Categorization constitutes a critical and adaptive solution to the challenges posed by both biological instability and environmental diversity. Categories refer to shared representations of like, but (usually) discriminable, entities, and are in evidence when organisms treat (discriminably) different entities equivalently. Categorization allows generalization across experience, because categorization relates experienced entities to one another and to their mental representation. Categories mediate our interactions with the world in many ways. They structure and clarify perception and cognition;they facilitate the storage and retrieval of information;and they supply a principle of organization by which new information is banked efficiently in memory. An entity that is encountered for the first time could be treated as unique or, if categorization is brought to bear, in the same way as previously encountered entities that it resembles. Categorization is also used to generalize about newly encountered entities from the same category. Knowledge about a category affords expectations about novel entities in toto as well as about features of novel entities. Categorization is thus a fundamental process by which the brain assigns meaning to sensory stimuli, and categorization is critical for rapidly and appropriately selecting behavioral responses. Categories are especially meaningful and valuable in infancy;without the ability to categorize, children would have to learn anew each novel entity they experience. In consequence, insights into how children first categorize are fundamental to understanding human cognition and development. What basic processes do infants employ in categorizing? One possibility is that infants categorize on line as they encounter and accrue experience with category-related entities;a second possibility is that infants depend on prior experience with entities in formulating categories. We experimentally tested these alternatives and found that 5-month infants who were familiarized in the laboratory with a category of never-before-seen objects subsequently treated novel objects of the same category as familiar -- that is, infants categorized on line -- just as did 5-month infants who were exposed to objects from the same category at home for 2 months leading to their assessment of object categorization in the laboratory. However, infants with home experience with the category also gave evidence that they recognized novel category objects as familiar from the outset that is, prior experience with category exemplars was brought to bear in laboratory tasks. Young preverbal infants appear to categorize entirely novel objects as they encounter them over even brief amounts of time, and infants also show they remember and apply categories learned on the basis of experience. A second study assessed specificity in parenting. Responsiveness defines the prompt, contingent, and appropriate reactions parents display to their children in the context of everyday exchanges. Maternal responsiveness occupies a theoretically central position in developmental science and possesses meaningful predictive validity over diverse domains of childrens development, yet basic psychometric features of maternal responsiveness are still poorly understood. In this prospective longitudinal study, we examined structure, individual variation, and continuity of multiple dimensions of responsiveness in mothers to their infants activities at 10, 14, and 21 months during natural home-based play interactions. Both age-general and age-specific patterns emerged in maternal responding. Our developmental results support the multidimensionality, modularity, and specificity of this central parenting construct. A third study employed a cross-national framework to examine country, region, and gender differences in emotional availability, a prominent index of mutual socioemotional adaptation in the parent-child dyad. Argentine, Italian, and U.S. American mothers and their daughters and sons from both rural and metropolitan areas took part in home observations at 20 months. In terms of country, Italian mothers were more sensitive and optimally structuring, and Italian children were more responsive and involving, than Argentine and U.S. dyads. In terms of region, rural mothers were more intrusive than metropolitan mothers, and boys from metropolitan areas were more responsive than boys from rural areas. In terms of gender, mothers of girls were more sensitive and optimally structuring than mothers of boys, and daughters were more responsive and involving than sons. Understanding how country, region, and gender influence emotional availability exposes forces that shape child development, parent-infant interaction, and family systems. A fourth study focused on emotional regulation in infants of clinically depressed mothers. Emotion regulation has been conceptualized as an ongoing process of the individuals emotion patterns in relation to moment-to-moment contextual demands. In contrast to traditional approaches of descriptively quantizing emotional regulation, we employed a dynamic approach to emotional regulation by examining key transitions in infants of clinically depressed and nondepressed mothers in the context of maternal still-face. Mothers with and without a clinical diagnosis of depression were seen with their 5-month-olds. Infant states and self-soothing behaviors were coded in 1-s time intervals. Infants of nondepressed mothers used attentional regulatory strategies, whereas infants of depressed mothers used internally directed strategies of self-soothing to reduce negativity and maintain engagement with mother. This study advances our understanding of processes underlying infant emotional regulation and points to possible mechanisms for the development of long-term maladaptive emotional regulation strategies in infants of depressed mothers.